Originally Posted by MN Scarab29 502

I have a 1993 Baja Islander 454, I was told 330 hp when I bought it. With the age I'm guessing the 330 has relaxed to 300hp. I get 63mpg on the GPS, at 4600rpm. The exhaust is running thru the prop today, and running a mirage 23. I've been told labing the prop should get me 2 to 3 mph, thru hull exhaust 1 or 2 mph. GIL headers 1 to 2 mph. So 4 to 7 mph, I'm getting some of it used for $1400 which should bring the boat 67 to 70 mph. Seems like a great trade off, without jeopardizing reliability. I wondering what your opinions are about the suggested mpg gains I've been told? Also wondering how many horsepower you guys think I'll be running, the stern of the boat has a "330hp" sticker on it, thinking of replacing it.

l'd really appreciate your opinions!